Dry cell



Aug. 23 1927.

B. K. BROWN DRY CELL Filed July '7, 1925 Patented A11-'g'. las, 1927.1,639,984

` UNITEDsTATEs PATENT foifFIcE. M

ERUGE x. RRoWN, or TERRE HAUTE, INDIANA, A ssIGNoR, BY MEsNE".AssIeN YMENTS, 'ro c. E.RURGfEss-I.ARoR.l'.vroR1Es,v 1N-c., 0E DovER, DELAWARE,A coR- PoRATIoN E DELAWARE. 1-

' The present invention relates to g'alvanicidrop 'in voltage to aboutfvolt on dis- 155v cells and more particularly to dry cells of charge,and a-pronounced lattening of the. i -the Le Clanchetype, wherein asolid depolar-v discharge curve. -'at this voltage.'y By coniizingmaterial is present at one electrode to bining thetwo v'depolarizer's invarious pro- '5 oxidize the hydrogen there set free. Y; Aportionsit ispossible to vmodify' the dis- Drv cells of 'theIifClanche t pe as nowcharge' curvev to suit the .requirements 60` constructed containfman'ganese dioxide in Thebxideof carbon maybe made by one or more ofits forms or combinations as fche'micalor by electrochemical oxidationand the depolarizing material. In ai copending may be ground in a ballmill or may be left application Serial No.A 42,090- filed July 7,unground and. can well-"be of' a inenessor` 1925, I have claimed a nevirgalvanic cell '20 mesh. using an oxideoffcarbon, such as graphitic A tpical liashligh mix follows, v,all oxide, as the'depolarizing medium. Inthe l'parts eing by wei-gh 5"parts oxide of present invention Isubstitute anoxide of 'carbon containing l7.85%- available'oxygen,

carbon, such as graphitic'oxide,`which has 15 par-ts manganese 'dfnr'ideiii-the form of depolarizing properties, fora portion ofthepyrolusite,:129,paijtsjpf pulverized graphite, 70 manganese dioxideusually used 'in dry hat? which maybe'of-theim alpable Iineness de-vteries.- v' scribed'in U. S.` 1 ?atent o.`1,162,449, i'parts The detailsofrny invention will become: of sal ammoniac, andi'-'afwettingvsolution. 20 clearer-from the following description taken The above 4,In'ixwill". lia've a considerably in conjunction with thedrawings herein:higher electrical* llfesistancel 'than a mix of the 75 `Fig 1- is alongitudinal'section of a dry same .proportions'butfo"which the 1 5partscell, and Fig. v2shows discharge curves for of oxideo'carbonihas-beenground in va ball dry cells when operating under conditions' milltocrackop'e'n' the oxidized particles. It hereinafter setiorthillVdetail. y l is also PQSSbIeO-SllbSU-te f01` the. *15P*arts In thedrawing the dry cell `comprises a of oxide of carbon'and'12partsofpulverized 80 seamless zinc cup' (1), which serves as a congraphitespecified-.inf theabove formula an tainer for .the other elements ofthe-cell. At 'oxide' :of caibQn :with llower oxygen content the'centerof the cup. is a carbonrod (2) and vwhich .has-beengroundto a inestateof *30 provided with a'brass cap y(3), and held in subdivision.;ltgisjalsp'ossible touse an.

place by`a seal '(4) -of pitch 'or sealingwax, equalamountof'artifficial manganese dioxide 85 poured in'while hotgandsupported on'a vin place -ofthe pyrolusite..

paper washer (5). Associated with the car- Iy havefurther 'discoveredthat: a highlyl 'non rod to form therewith the cathode of the eiicientfdepolarizing mixture may be made cell isa tightly compacted ormolded'block by recipitating anarticial manganesedi-v (6) ofdepolarizing mixture. This may ber oxie onto the oxidized'carbonparticles. A.1 00 enclosed in a v'cheese cloth envelope (7)-,-'believethat thefincreased efiiciency resulting wrap ed'aroundwithathread'(8) Agelatfrom this method is due to the actual pre1 inized)electrolyte (9) separatesthe c'atho'de cipitation \ofthe" manganes`edioxide in the -4=0 from-the anode, as will be understoodby voxide oi,carbon; the exi-de being' colloidal f those skilled in theart. 'j andVtherefore; able to absorb thes'olutions 95 When manganese dioxide -isused for de7 used for preparing the manganese dioxide. 'polarizinga drycell, the discharge curve The man anese dioxide'may be'precipitated hascertain characteristics as illustrated 'in fby any o the knownmethodsfor preparing` curve (A) of Fig. 2, where voltages haveVartificial manganese dioxide.- Following isg been plotted against timein minutes for cona' specification of a typical run which -I have 10 0tinuous discharge of a typical cell through a jf oundto give excellentV- results: 1500 grams four ohm resist-ance, the cell being -o'f a sizeof graphite oxidized to contain 4.22 per cent 5/8 in diameter and 17/8tall.

' 50 When oxidized carbon is used asthe de .suspended in the followingsolution: y

polarizer the discharge curve has somewhat 450 grams potassium vpermanganato, 16 105v different characteristics as shown by curve literswater, c. c. nitric acid conc., 425 (B) of Fig. 2, being characterizedby lower grams 'manganese sulphate dissolved in one open and closedcircuit voltages, a quick liter of water. This mixture is agitatedpcoffixed-'oxygen (ground-or ungroundl)l arci Y casionally for a 24 hourperiod after which it is Washed, filtered and dried. rl`lie yield shouldbe over 1900 grams of solid.

rllhe above mixture may be used in the following proportions for makinga depolarizing mixture for dry cells:

30 parts manganese-treat-ed oxide of carbon, 12 parts impalpablegraphite, 4 parts sal ammoniac, the mass being wetted to the usualconsistency.

Cores or cathodes are tamped in thevusual manner as by aid of a tampingmachine, such as is shown in U. S. Letters Patent No. 1,232,297, issuedJuly 3, 1917. The cores are then assembled in a zinc can using agelatinizable electrolyte to separate the molded electrode from thezinc.` vSuitable electrolytes are disclosed in U. S. Letters Patents No.1,292,764, issued January 28, 1919, and No. 1,370,056, issued March 1,1921. The molded electrode may be provided With a cheese cloth or otherbibulous envelope as disclosed in the latter patent, or may be leftuncovered as disclosed in the earlierv patent.

r1hroughout the specifications andclaims carbon and carbonaceousmaterial is used in the broader sense and includes the graphitic stateof the element.

v1. A galvanic'cell containing a depolarizer comprising manganesedioxide and oxidized carbon.

'. 2. A galvanic cell containing a depolarizer comprising artificialmanganese dioxide and oxidized carbon.

3. A galvanic cell containing a depolarizer comprising oxidized carbonupon which artificial manganese dioxide has been precipitated. j 4 v 4.A. galvanic cell containing a depolarizer comprising manganese dioxideand car bonaceous material partly oxidized to oxide ot'carbon. i

5. A galvanic cell containing a depolarstantially as described. o

izing rnixture comprising oxidized carbon,

manganese dioxide, suitable salts and water..

6, A mixture for electric batteries containing conductive carbonaceousmaterial, oxide of carbon, and manganese dioxide.

7. A mixture for electric batteries containing conductive -carbonaceousmaterial,

8. A. mixture for electric batteries containing'the followingingredients in about the proportions state 30 parts man anese treatedoxide of carbon, 12 part-s impa pable graphite, 4 parts sal ammoniac,and Water for wetting to the usual consistency, sub- 9. A molded cathodefor a galvanic cell containing oxide of carbon and manganese dioxide.

10. A galvanic cell having a zinc electrode and a cathode core thereforcontaining oxide of carbon and .manganese dioxide as depolarizers.

11. lln a galvanic cell, the combination o a zinc container, a vtarbonrodsupported therein, a depolarizing mixture inclosing said rod andconsisting essentially of a conductive carbonaceous material, oxide ofcarbon and manganese dioxide, together with the usual saltsand-vvatei-,and a gelatinized paste separating said depolarizing mixturefrom the zinc container.

12.' The method of controlling the discharge curve of an electricbattery which consists in proportioning the ratio of oxide of carbon tomanganese dioxide used for depolarizing the battery.

In testimony whereof I afiix my signature.

BRUCE K; BROWN.

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